Many Wireless Wide Area Networks (WWAN) employ some form of Time Division Duplexing (TDD) to schedule both Down Link (DL) and Up Link (UL) traffic. In a TDD environment, DL and UL communications occur between a cellular radio tower (tower) and wireless mobile devices within a geographic area covered by the tower that is referred to as a cell. DL communications from the tower to the wireless mobile devices occur during a first set of timeslots. Conversely, UL communications from the wireless mobile devices to the tower occur during a second, non-overlapping set of timeslots. The collection of timeslots for which a tower schedules radio resources for UL and DL communications describes the UL-DL configuration, or TDD configuration, for the tower and its corresponding cell.
Unfortunately, when differing, or asynchronous, UL-DL/TDD configurations are adopted at different transmission points within a WWAN, interference can become a problem. The DL transmission of one tower can interfere with the UL reception at another tower. Similarly, the UL transmissions of one wireless device can interfere with the DL reception at another wireless device. To avoid such interference, entire WWANs can operate synchronously, with a common UL-DL/TDD configuration.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.